title: Genome-wide transcript profiling of endosperm without paternal contribution identifies parent-of-origin-dependent regulation of AGAMOUS-LIKE36.
abstract: Seed development in angiosperms is dependent on the interplay among different transcriptional programs operating in the embryo, the endosperm, and the maternally-derived seed coat. In angiosperms, the embryo and the endosperm are products of double fertilization during which the two pollen sperm cells fuse with the egg cell and the central cell of the female gametophyte. In Arabidopsis, analyses of mutants in the cell-cycle regulator CYCLIN DEPENDENT KINASE A;1 (CKDA;1) have revealed the importance of a paternal genome for the effective development of the endosperm and ultimately the seed. Here we have exploited cdka;1 fertilization as a novel tool for the identification of seed regulators and factors involved in parent-of-origin-specific regulation during seed development. We have generated genome-wide transcription profiles of cdka;1 fertilized seeds and identified approximately 600 genes that are downregulated in the absence of a paternal genome. Among those, AGAMOUS-LIKE (AGL) genes encoding Type-I MADS-box transcription factors were significantly overrepresented. Here, AGL36 was chosen for an in-depth study and shown to be imprinted. We demonstrate that AGL36 parent-of-origin-dependent expression is controlled by the activity of METHYLTRANSFERASE1 (MET1) maintenance DNA methyltransferase and DEMETER (DME) DNA glycosylase. Interestingly, our data also show that the active maternal allele of AGL36 is regulated throughout endosperm development by components of the FIS Polycomb Repressive Complex 2 (PRC2), revealing a new type of dual epigenetic regulation in seeds.
authors.affiliation: Department of Molecular Biosciences (IMBV), University of Oslo, Oslo, Norway.
authors.forename: Reza
authors.initials: R
authors.lastname: Shirzadi
authors.forename: Ellen D
authors.initials: ED
authors.lastname: Andersen
authors.forename: Katrine N
authors.initials: KN
authors.lastname: Bjerkan
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Gloeckle
authors.forename: Maren
authors.initials: M
authors.lastname: Heese
authors.forename: Alexander
authors.initials: A
authors.lastname: Ungru
authors.forename: Per
authors.initials: P
authors.lastname: Winge
authors.forename: Csaba
authors.initials: C
authors.lastname: Koncz
authors.forename: Reidunn B
authors.initials: RB
authors.lastname: Aalen
authors.forename: Arp
authors.initials: A
authors.lastname: Schnittger
authors.forename: Paul E
authors.initials: PE
authors.lastname: Grini
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D056625:Endosperm / Q000235:genetics* / Q000254:growth & development; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant / Q000235:genetics; D018745:Genome, Plant / Q000235:genetics*; D018392:Genomic Imprinting; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D008957:Models, Genetic; D009699:N-Glycosyl Hydrolases / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
chemical_list: C559925:AGL36 protein, Arabidopsis; D029681:Arabidopsis Proteins; D026161:MADS Domain Proteins; D015534:Trans-Activators; C499608:MET1 protein, Arabidopsis; D004248:DNA (Cytosine-5-)-Methyltransferases; C463261:DEMETER protein, Arabidopsis; D009699:N-Glycosyl Hydrolases